Category: Technology

I built a d-bot 3D printer by using my other 3D printer to print out a lot of the parts for it.

It took about 6 weeks to print the pieces, and another month of long nights to get it assembled. Some pieces had to be reordered. Lots of nonsense.

Sam, why would you do this?

Glad you asked. The new printer is faster, ~2 times bigger, $100 less expensive, and generally better than my current one. The ability to use tools to create better tools is something that blows my mind. Plus, it’s just awesome to be able to download physical tools from the internet.

How does it work?

It moves a nozzle that pushes melted plastic around on a plane to build up a layer of plastic. Then, the floor drops down a bit, and it repeats the process. This builds up hundreds or thousands of layers that form into a 3D shape.

3D Printer Build Gallery

Let me see something you printed.

What tools and parts do you need to build this?

A 3D printer, or a friend with one, some cheap electrical tools, and a bunch of wire, servos, and Arduinos (well, I burned a few controller boards, so if you’re good, just one). Parts list and 3D models can be found here. I didn’t have much electrical experience before this project, and I’m no expert now. The included guide was really thorough, luckily. Still, there was a lot of trial and error.

How much did it cost?

Around $650, plus a lot of blood, sweat, and time.

Would you build another one?

It would probably be a lot faster than the first time, but I think for my next printer, I’d get something lower-maintenance. Moving forward, I want to focus on 3d design and finishing, not leveling my print bed.

Hey there! I hope you have some fun Thanksgiving plans that include lots of gorging yourself and relaxing. Today’s song is an old favorite of mine.

I’ve been looking for a project for my Tessel2 microcontroller for a few months now. It’s cool because it allows you to program hardware using Javascript, which is my favorite.

With the coming holidays, I’ll be traveling for a few days. Since I’m the proud father of a Betta fish named Rhaegar, I wanted to make sure he stayed alive and happy, so I decided to make him an automatic fish feeder.

Then, I did lots of testing. I needed to make sure the amount of food was consistent in each feeding, which was exceedingly difficult. I decreased the time between feedings and tried both worms and pellets to see which was the easiest to produce consistent results, and ended up with a mixture of both.

Everyone knows that interest rates are abysmally low nowadays, especially for savings accounts in the US. When I was younger, I remember speaking with my grandfather, who recommended investing in Certificates of Deposit for 1-to-5-year savings at 5%.

Now, my TD Bank savings account has an interest rate so low, they just round it to 0.00 on my statements, and the best CD I can find today is 1.10%. The best liquid savings I’ve found is Ally, where I store my emergency fund, at 1%. Our government wants to stimulate economic growth by discouraging saving (they call it hoarding to make it sound bad) money, so the Fed sets incredibly low interest rates for everything (except student loans; can I get an Amen?!).

Terrible economic policy discussions aside, I’ve found a couple ways to help lessen the pain of saving.

As part of diversifying my savings, I have money in a 401k + Roth IRA through my work, and a small percentage in commodities like gold and Bitcoin that I set up by myself.

In May, as an experiment, I set up an account at BitBond, a peer-to-peer lending service, which was advertising an average yield of over 20% APY. Essentially, I view it as a slightly riskier CD. People ask for loans for various business ventures and explain their income and repayment plan, and you can bid as low as .01 Bitcoin (~$4 at the time I bid) on their loan.Each of the loans is assigned a rating based on the history of the loanee and his income, and you can choose to loan in either US Dollars or Bitcoin, with Bitcoin as the source.

I dropped in $40 worth of bitcoin that I didn’t mind losing to see what would happen. Here’s my results, and a comparison to my TD Bank savings account, in which I left exactly $1000 after transferring my savings to Ally, just to keep the account active.

Results

After two months, my TD account made 6 cents of interest. Here’s one month’s payment for proof:

As you can see above, each loan is classified A-F, with A being the highest rating and the lowest interest, and F being the most risky, with greatest chance of reward. I’ve diversified my loans by putting the minimum in most of the loans and spreading out the risk by investing in different classes of loan, A through E.

In the same time on Bitbond, I’ve received 60 cents in interest, or 10 times more interest with 25 times less principal invested. They project that I’ll be getting 23% APY based on my investments spread this year.

Final Words

Now that we’ve seen the numbers, I’d like to point out a couple things. This method of investing is significantly riskier than a normal bank account – as you can see above, two of my loanees are late on their payments, which means I’ve gotten no interest on them. There’s a nonzero chance I’ll never get that money back. I justify this by making sure I don’t care about getting this money back, and that it’s a very small portion of my overall portfolio, and by diversifying my loan choices.

Secondly, Bitcoin is a relatively new and unstable currency (though, it might be more stable than the Pound right now! Zing.) It is, however, an incredibly exciting and useful technology that I choose to support with my dollars. There is a chance that the price of Bitcoin will fluctuate enough that the growth of the currency itself might outpace the interest you receive from this investment. If you want to learn more about Bitcoin investment, reddit.com/r/bitcoin, reddit.com/r/cryptocurrencies, and reddit.com/r/bitcoinmarkets are fantastic resources.

Also, I’m not sure if these results will scale linearly with more money invested. There might be a point of diminishing returns with P2P lending, and I might put in some more money to test the waters, but I don’t want to be overly optimistic.

Finally, I want to reiterate that I am not, by any means, an expert in finance, Bitcoin, or cryptocurrency. This is just something that I’ve been studying on my own for a while and wanted to share with you.

Good morning and Happy Friday! I’m back after a little prompting from an old friend.

Song of the day:

Quick life update: I’m living near New York City now, and I’m working as a Senior Software Engineer for a team that writes the software that supports such excellent blogs as Engadget, Huffington Post Australia (more international editions to follow!), and Autoblog, among many others.

I’ve also gotten way into 3D printing, Internet of Things development, and am still doing minor development on my open-source fitness project, PPL.fitness.

Enter stage right:Nightwatch.js. Super simple to set up. I get to use Node.js to simulate clicks, typing, and key presses, and check to see if elements are visible. I also get to check properties of the elements. Plus, it runs against the industry-standard Selenium server.

Though the initial setup took about a day to get my code decently covered by tests, I can now rest a little easier knowing that when I release new feature updates to my software, everything will work.

//this is where we make our actual comparisons to see if everything is working!
client.expect.element(‘#template-container .headline-1 .splash__header’).text.to.equal(‘Automated Testing Is the Best!’);
client.expect.element(‘#template-container .headline-1 .splash__header’).to.have.css(‘font-size’, ’80px’);
client.expect.element(‘#template-container .headline-1 .splash__header’).to.have.css(‘color’, ‘#2D7061’);

client.end();
}
};
[/code]

As you can see, the syntax is really simple!

[code]

expect(elementSelector).to.have.css(style, value)

expect(elementSelector).text.to.equal(value)

[/code]

I am even able to test the type of my remote data store’s JSON schema with it by running AngularJS commands using client.api.execute(command)!

Good morning everybody! I strongly recommend you let this song melt into your ears while you read.

It’s been a busy couple of weeks for me! I’ve been working on a big feature release at work, and in my free time, I’ve also been working on arkWatcher and ojo, two open-source Javascript projects. I ran into an issue with some of arkWatcher’s functionality that I posted to StackOverflow, and ended up getting some excellent guidance from my brilliant coworker Michael Timbrook. He suggested using Reactive Extensions to solve my problem, so I’ve been reading up on it the past day or two. It’s really cool, and builds quite simple functions into complex functions to solve big problems. So far, I’ve found this awesome YouTube video and this guide to help me learn more about it.

In other, non-programming, news, I’ve been swimming a ton lately. I love it, and it’s fun, but it’s made me noticeably more tired and hungry lately, so I probably have to eat more.

Speaking of eating more, check out this breakfast sandwich I custom-ordered at Lucky Donuts and Deli. Two glazed donuts, scrambled eggs, excellent bacon, and bubbly cheese. This was, without a doubt, the most craving-satisfying, stomach-filling, rich, delicious thing I’ve eaten in a long time.

I’m of the firm belief that you have to have a cheat meal once in a while, at least. This near-obscene, perfect sweet-and-salty combination is the cheatiest of all meals.

This month is just flying by, and I still haven’t come up with a Halloween costume. It’s weird – being on the West Coast for the first time, it doesn’t feel like Fall yet, so some part of me is in denial about what time of year it is. But the days are getting shorter. My friends back at home sent me tons of pictures of hail and snow and 20 degree temperatures last weekend, which seems a little early, even for the Northeast, although this week was apparently a gorgeous one. Here in San Diego, it’s been pretty nice with some occasional rain and cool temperatures. Here was the view on my porch this morning:

Yeah, I live next to a freeway. And a construction site. It’s pretty loud sometimes.

Pool’s nice, though.

This month, I really started pushing myself more physically, mentally, and with my work. I’m starting to enjoy and see great benefit from pushing past the limits of my comfort zone and moving as far into the learning zone as I can. I’m working on finding small optimizations that give me more time, and then using that time to get stronger.

The other day, my buddy asked my advice about which things he should prioritize in his life and which he should drop. The problem was – all the items he wanted me to choose from were equally important. The only answer I could give him in good conscience was that he had to do them all. If they’re all critically important items, what other choice does he have?

Sometimes, it feels like we have the barest illusion of choice; really, we have no true choice at all. Sometimes we just have to stay awake later than we want; sometimes we have to concentrate longer and harder, and do more, than we ever thought possible. Sometimes, everything seems to go wrong all at once.

Important in my examination of these ideas is remembering how lucky we are to be given these challenges in the first place. How lucky we are that we have people all around us who’ve gone through similar things! I’m starting to treat each challenge as a gift, a lesson, and a test. A way to glean as much as possible from the brilliant and amazing people around me.

Lately, I’ve been looking into tracing the route of service calls through chained services. Since many companies are moving toward a Service-Oriented-Architecture model, tracing when services are called is a crucial step in debugging. This way, when there’s an issue with a service, we know which one is breaking and causing everyone downstream to fail.

As a quick example of what I’m talking about, I’ve made a simple model:

Service A: returns “Hello”

Service B: returns “world”

Service C: calls A and B, then returns “Hello world”

Now, imagine service B is taking a long time to respond. Service C will be stuck, and we couldn’t be sure whether it was A or B who is causing the problem!

My goal is to get in the middle of those calls to services A and B and attach headers that track when those calls are made. First, I tried digging into my services’ Bunyan() logging modules and adding my interceptors there. Didn’t work.

Instead, after asking around work and on StackOverflow, I’ve decided to make my own NodeJS module that wraps around Request() and handles all of this for developers with them doing a minimal amount of work. Here’s what I came up with:

I was recently tasked with validating an input field – comparing whatever someone typed with a list and making sure there aren’t any duplicates. Here’s what I did:

Install Angular-UI-Validate. I chose to use this library because of its ability to skip the hassle of writing custom formatters and easy integration with Angular. Make sure to add it as a module in app.js!

[code lang=”js”]

angular.module(‘app’, [ui.validate’])

[/code]

In the controller, I had to add a function that checked the value passed to it against a list of names.

In the ui-validate property, the input is labeled as taken if the $scope.nameHasNotBeenUsed function returns false. Then, ng-class takes over: it checks for formName.inputName.$error.taken, and if it’s present, it applies the class permission-input-wrong (this just outlines the field in red).

Another cool thing we are doing is selectively hiding and showing error messages based on that formName.inputName.$error.taken.

Thanks for reading! If this helps you – if this is a dumb way of doing this, and I need to be corrected – tell me in the comments!

Even though most of us have an idea about what NFCs are and what they can do, we shun the thought of using them due to their lack of application in our lives. Well, I’m here to tell you, that’s finally changed. With the help of few dollars, you can take automate your mundane activities and have your mobile phone take care of it for you.

No, this does not require any expensive sensors, hardware or fobs, just a few NFC tags that can hold a little “ID” data for you. NFC tags are pretty great. They are small, paper-like and hold 450 bytes of writable memory. Apologies for getting really technical, but I am here to show you that irrespective of your depth of knowledge in technology, you can do some really nifty things with NFC.

I am going to write a small tutorial on what you can do and how with some examples to make it abundantly clear.

Once you buy these NFC tags, we need to tell your phone what to do when the NFC is detected by it. Needless to say, you’re going to require an NFC enabled phone. With the help of apps that implement the IFTTT technology. You can set action triggers, conditions and finally, actions for your phone to do. I use Automatic Premium, but there are other free alternatives too. We are going to define a flow for this, which is nothing but a simple, graph-like structure that gives basic instructions to your phone.

Let’s go ahead and tell our app to listen for a particular NFC tag (each NFC has it’s own unique ID)
Reading for a new Tag will simply open up the wizard UI and wait patiently for you to tap the NFC tag gently on the backside of your phone.

Once you do, the app reads the “ID” data that uniquely defines an NFC tag. For the sake of this demo, let’s give this NFC ID a nick name, i.e. “Sleep”.

Next, we tell the app what to do when this NFC Tag is detected. This can be done using the IFTTT app. With the help of simple triggers, conditions and actions to perform we can automate simple tasks.
Here’s an example: Every night before sleeping I turn my data and wifi off and enable battery saving mode. This practice helps to improve my battery life.
Like I mentioned before, if there is absolutely any activity that is performed repeatedly it can be automated complete. So I quickly drag and drop some boxes on the app’s graph UI and tell it what to do.

All I am doing is telling the app to perform the following actions if at all the NFC Tag is detected (Trigger). Check if the time is between 9pm to 7am (Condition), if true set the data / wifi state to off and turn on battery saving mode (action).

Trust me when I say this: making these simple flows is one of the easiest things I have ever done. I encourage everyone to at least give it a shot. There are tons of other applications of these tags and tools: Tapping the tag on your car dashboard starts data, location and opens your maps app for guidance. You’re only limited by your own imagination.

The good news: Over four thousand impressions. That’s pretty cool. 81 clicks is decent.

The bad news: these impressions didn’t really translate into more people downloading my application. I now hover around 35 active weekly users, up from around 25. This is awesome, but I have a feeling that these additional users are more due to my buddy Avanish promoting my app on his social media channels.

I’m probably going to close this campaign. It was fun, and a good learning experience, but since I’m not making any money from the application, it doesn’t benefit me to continue marketing it.

My friend and co-worker Ashpak Shaikh asked me to put together a how-to on a personal website like mine, so I figured I’d write it up as a blog post, just in case anyone else wants to do something similar. It’s super simple, cheap, and easy to maintain.

1) Buy a domain name.

I’ve been using nameCheap.com for a few years now with no problems. I’ve been advised to avoid GoDaddy for numerous reasons, so I can’t really speak to the pros and cons of each service. I can say that NameCheap has everything I need at a cheap price. It’s just a domain name, don’t go crazy with it.

Also – if you find a domain name you like that’s open, snatch it up as soon as you can. People have written scripts that buy up domain names after they’ve been searched, then they sell the name for a profit. They’re assholes.

2) Find some hosting.

I use Amazon EC2, which was free for my first year, and has been averaging around $13-15 per month since. It gives you full terminal access for any imaginable kind of server – Ubuntu, Red Hat, CentOS, even Windows. It also scales automatically if more people visit the site, with the ability to limit the scaling to a dollar amount.
There are cheaper services, namely DigitalOcean. I haven’t used them. Again, whatever floats your boat is fine here.